Transversal actuator for haptic feedback

ABSTRACT

An actuator configured to provide haptic feedback to a user. The actuator is located on a plate and is configured to apply various excitations to the plate to generate a mechanical wave propagating in the controlled direction. The excitations can be a translational motion of the actuator (or a portion of the actuator) in two or three perpendicular axes. Alternatively, the excitations can be a non-translational motion (e.g., rotation about an axis) of the actuator (or a portion of the actuator). By generating the mechanical wave traveling in the controlled direction, loss of energy due to scattering of the mechanical wave can be obviated.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 62/232,824 filed on Sep. 25, 2015 and U.S.Provisional Patent Application No. 62/232,815 filed on Sep. 25, 2015,which are incorporated by reference in their entirety.

BACKGROUND

The present disclosure generally relates to a system for presenting avirtual reality experience to a user, and specifically to an actuatorfor providing haptic feedback to the user.

A virtual reality system enables a user to experience a virtual reality.The virtual reality system creates a virtual world, and presents athree-dimensional (3-D) image of the virtual world to a user. Thevirtual reality system updates the visual illustration of the virtualworld according to a user's movement, so that the user can visuallyexperience the virtual world. The virtual reality system can alsoprovide haptic feedback to the user. Specifically, the virtual realitysystem provides to the user haptic feedback that the user can sense inconjunction with the 3-D image of the virtual world to amplify thevirtual reality experience.

In one example, the virtual reality system implements actuatorsproviding haptic feedback that a user can sense. Actuators coupled to anedge of a haptic surface can vibrate, for example through an up and downexcitation, to generate a wave to provide haptic feedback to the user.However, the wave generated by the actuators vibrating through thesimple up and down excitation is scattered omni-directionally ratherthan being propagated in a controlled (or desired) direction toward theuser. Therefore, there is a loss of energy delivered to the user on thehaptic surface. Moreover, damping elements may need to be implemented toreduce reflections of waves propagated in untargeted directions.

SUMMARY

Embodiments relate to an actuator configured to generate a mechanicalwave that propagates through a plate. The plate may be a haptic mat onwhich a user can stand on. The actuator comprises: a first magnet havinga pole, the first magnet coupled to the plate; and a first body, thefirst body comprising: a first elongated member, a first end of thefirst elongated member facing a first surface of the first magnet, asecond end of the first elongated member facing a second surface of thefirst magnet, a first coil coupled to the first end of the firstelongated member, and a second coil coupled to the second end of thefirst elongated member. The first elongated member may include amaterial which forms a medium with a magnetic permeability within apredetermined range for directing magnetic flux. The first coil and thesecond coil are configured to be driven with a first electric currentand a second electric current, respectively, that together induce amagnetic field within the first elongated member to cause a motion ofthe first magnet relative to the first body, the motion of the firstmagnet generating some or all of the wave within the plate.

In one or more embodiments, the actuator further comprises: a secondmagnet having another pole, the second magnet coupled to the plate; anda second body, the second body comprising: a second elongated member, afirst end of the second elongated member facing a first surface of thesecond magnet, a second end of the second elongated member facing asecond surface of the second magnet, a third coil coupled to the firstend of the second elongated member, and a fourth coil coupled to thesecond end of the second elongated member. The third coil and the fourthcoil may be configured to be driven with a third electric current and afourth electric current, respectively, that together induce anothermagnetic field within the second elongated member to cause a motion ofthe second magnet relative to the second body, the motion of the secondmagnet together with the motion of the first magnet generating some orall of the wave within the plate. A third end of the first body awayfrom the first magnet may be coupled to a third end of the second bodyaway from the second magnet. The first body and the second body may becoupled to each other to form a ferrite.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a system environment including a virtualreality system, in accordance with an embodiment.

FIG. 2 is a diagram of a user on a haptic mat of the virtual realitysystem including actuators, in accordance with an embodiment.

FIG. 3A is a perspective view of an example actuator, in accordance withan embodiment.

FIG. 3B is a front view of the actuator of FIG. 3A, in accordance withan embodiment.

FIG. 3C is a bottom plan view of the actuator of FIG. 3A, in accordancewith an embodiment.

FIG. 3D is a side view of the actuator of FIG. 3A, in accordance with anembodiment.

The figures depict embodiments of the present disclosure for purposes ofillustration only. One skilled in the art will readily recognize fromthe following description that alternative embodiments of the structuresand methods illustrated herein may be employed without departing fromthe principles, or benefits touted, of the disclosure described herein.

DETAILED DESCRIPTION Configuration Overview

Embodiments relate to an actuator for providing haptic feedback to auser or a part of a user (e.g., user's hand) on a plate in a controlleddirection. The actuator is located on the plate and is configured toapply various excitations to the plate to generate a wave propagating inthe controlled direction. The excitations can be a translational motionof the actuator (or a portion of the actuator) in two or threeperpendicular axes. Alternatively, the excitations can be anon-translational motion (e.g., rotation about an axis) of the actuator(or a portion of the actuator). By generating the wave traveling in thecontrolled direction, loss of energy due to scattering of the wave canbe obviated.

In one or more embodiments, multiple actuators are placed on the plateand controlled to generate multiple waves. Multiple waves from themultiple actuators can be combined through interference into a singlewave and propagated to a destination (e.g., a user) having a desiredwaveform in a desired direction.

In one or more embodiments, an actuator includes a magnet having atleast three surfaces and a body configured to create magnetic field thatinteracts with magnetic field from the magnet. In one example, themagnet has a first surface coupled to the plate, a second surface facingone end of the body in a slanted direction (or a transversal direction)from a parallel direction of the plate or the orthogonal direction ofthe plate, and a third surface facing another end of the body in anotherslanted direction from the parallel direction of the plate or theorthogonal direction of the plate. In this configuration, the magnet canbe moved in any direction along a two dimensional space crossing theplate according to magnetic field applied from two ends of the body.

In one or more embodiments, the actuator includes two magnets and twobodies forming a cubic structure. Two magnets are coupled to the plate,and two ends of each body face one of the two magnets. Each of the twobodies is capable of creating magnetic field that interacts withmagnetic field from a respective magnet to form a net magnetic field ina transversal direction to the parallel direction of the plate or theorthogonal direction of the plate, thereby imparting force on bothbodies. The actuators can be driven with heterogeneous signals orsignals delayed in time. In this configuration, the actuator can applyvarious actuations (e.g., a whipping motion) to the plate to generate adesired wave.

In one aspect, one or more actuators on one side of the plate can beconfigured to actuate the plate in response to an incoming wave tocancel (or suppress) the incoming wave. This can be performed bygenerating a destructive interference, or dampening energy of theincoming wave. The one or more actuators can be operated according to aprediction of the wave including, for example, a type of wave,frequency, amplitude, estimated time of arrival of the feedback wave,and etc.

System Overview

FIG. 1 is a block diagram of a virtual reality (VR) system environment100 in which a VR console 110 operates. The system environment 100 shownby FIG. 1 comprises a VR headset 105, an imaging device 135, a VR inputinterface 140, and a haptic device 180 that are each coupled to the VRconsole 110. While FIG. 1 shows an example system 100 including one VRheadset 105, one imaging device 135, and one VR input interface 140, inother embodiments any number of these components may be included in thesystem 100. For example, there may be multiple VR headsets 105 eachhaving an associated VR input interface 140 and being monitored by oneor more imaging devices 135, with each VR headset 105, VR inputinterface 140, and imaging devices 135 communicating with the VR console110. In alternative configurations, different and/or additionalcomponents may be included in the system environment 100. Similarly, thefunctions can be distributed among the components in a different mannerthan is described here. For example, some or all of the functionality ofthe VR console 110 may be contained within the VR headset 105.

The VR headset 105 is a head-mounted display that presents media to auser. Examples of media presented by the VR head set include one or moreimages, video, audio, or any combination thereof. In some embodiments,audio is presented via an external device (e.g., speakers and/orheadphones) that receives audio information from the VR headset 105, theVR console 110, or both, and presents audio data based on the audioinformation.

The VR headset 105 includes an electronic display 115, an optics block118, one or more locators 120, one or more position sensors 125, and aninertial measurement unit (IMU) 130. The electronic display 115 displaysimages to the user in accordance with data received from the VR console110.

The optics block 118 magnifies received light from the electronicdisplay 115, corrects optical errors associated with the image light,and the corrected image light is presented to a user of the VR headset105. An optical element may be an aperture, a Fresnel lens, a convexlens, a concave lens, a filter, or any other suitable optical elementthat affects the image light emitted from the electronic display 115.Moreover, the optics block 118 may include combinations of differentoptical elements. In some embodiments, one or more of the opticalelements in the optics block 118 may have one or more coatings, such asanti-reflective coatings.

The locators 120 are objects located in specific positions on the VRheadset 105 relative to one another and relative to a specific referencepoint on the VR headset 105. A locator 120 may be a light emitting diode(LED), a corner cube reflector, a reflective marker, a type of lightsource that contrasts with an environment in which the VR headset 105operates, or some combination thereof. In embodiments where the locators120 are active (i.e., an LED or other type of light emitting device),the locators 120 may emit light in the visible band (˜380 nm to 750 nm),in the infrared (IR) band (˜750 nm to 1 mm), in the ultraviolet band (10nm to 380 nm), some other portion of the electromagnetic spectrum, orsome combination thereof.

In some embodiments, the locators 120 are located beneath an outersurface of the VR headset 105, which is transparent to the wavelengthsof light emitted or reflected by the locators 120 or is thin enough notto substantially attenuate the wavelengths of light emitted or reflectedby the locators 120. Additionally, in some embodiments, the outersurface or other portions of the VR headset 105 are opaque in thevisible band of wavelengths of light. Thus, the locators 120 may emitlight in the IR band under an outer surface that is transparent in theIR band but opaque in the visible band.

The IMU 130 is an electronic device that generates fast calibration databased on measurement signals received from one or more of the positionsensors 125. A position sensor 125 generates one or more measurementsignals in response to motion of the VR headset 105. Examples ofposition sensors 125 include: one or more accelerometers, one or moregyroscopes, one or more magnetometers, another suitable type of sensorthat detects motion, a type of sensor used for error correction of theIMU 130, or some combination thereof. The position sensors 125 may belocated external to the IMU 130, internal to the IMU 130, or somecombination thereof.

Based on the one or more measurement signals from one or more positionsensors 125, the IMU 130 generates fast calibration data indicating anestimated position of the VR headset 105 relative to an initial positionof the VR headset 105. For example, the position sensors 125 includemultiple accelerometers to measure translational motion (forward/back,up/down, left/right) and multiple gyroscopes to measure rotationalmotion (e.g., pitch, yaw, roll). In some embodiments, the IMU 130rapidly samples the measurement signals and calculates the estimatedposition of the VR headset 105 from the sampled data. For example, theIMU 130 integrates the measurement signals received from theaccelerometers over time to estimate a velocity vector and integratesthe velocity vector over time to determine an estimated position of areference point on the VR headset 105. Alternatively, the IMU 130provides the sampled measurement signals to the VR console 110, whichdetermines the fast calibration data. The reference point is a pointthat may be used to describe the position of the VR headset 105. Whilethe reference point may generally be defined as a point in space;however, in practice the reference point is defined as a point withinthe VR headset 105 (e.g., a center of the IMU 130).

The IMU 130 receives one or more calibration parameters from the VRconsole 110. As further discussed below, the one or more calibrationparameters are used to maintain tracking of the VR headset 105. Based ona received calibration parameter, the IMU 130 may adjust one or more IMUparameters (e.g., sample rate). In some embodiments, certain calibrationparameters cause the IMU 130 to update an initial position of thereference point so it corresponds to a next calibrated position of thereference point. Updating the initial position of the reference point asthe next calibrated position of the reference point helps reduceaccumulated error associated with the determined estimated position. Theaccumulated error, also referred to as drift error, causes the estimatedposition of the reference point to “drift” away from the actual positionof the reference point over time.

The imaging device 135 generates slow calibration data in accordancewith calibration parameters received from the VR console 110. Slowcalibration data includes one or more images showing observed positionsof the locators 120 that are detectable by the imaging device 135. Theimaging device 135 may include one or more cameras, one or more videocameras, any other device capable of capturing images including one ormore of the locators 120, or some combination thereof. Additionally, theimaging device 135 may include one or more filters (e.g., used toincrease signal to noise ratio). The imaging device 135 is configured todetect light emitted or reflected from locators 120 in a field of viewof the imaging device 135. In embodiments where the locators 120 includepassive elements (e.g., a retroreflector), the imaging device 135 mayinclude a light source that illuminates some or all of the locators 120,which retro-reflect the light towards the light source in the imagingdevice 135. Slow calibration data is communicated from the imagingdevice 135 to the VR console 110, and the imaging device 135 receivesone or more calibration parameters from the VR console 110 to adjust oneor more imaging parameters (e.g., focal length, focus, frame rate, ISO,sensor temperature, shutter speed, aperture, etc.).

The VR input interface 140 is a device that allows a user to send actionrequests to the VR console 110. An action request is a request toperform a particular action. For example, an action request may be tostart or end an application or to perform a particular action within theapplication. The VR input interface 140 may include one or more inputdevices. Example input devices include: a keyboard, a mouse, a gamecontroller, or any other suitable device for receiving action requestsand communicating the received action requests to the VR console 110. Anaction request received by the VR input interface 140 is communicated tothe VR console 110, which performs an action corresponding to the actionrequest. In some embodiments, the VR input interface 140 may providehaptic feedback to the user in accordance with instructions receivedfrom the VR console 110. For example, haptic feedback is provided whenan action request is received, or the VR console 110 communicatesinstructions to the VR input interface 140 causing the VR inputinterface 140 to generate haptic feedback when the VR console 110performs an action.

The haptic device 180 is a device configured to provide haptic feedbackto the user. The haptic device 180 is operated according to commandsfrom the VR console 110. Specifically, the haptic device 180 providesactuation that a user can sense, in accordance with the image presentedon the VR headset 105. For example, the haptic device 180 vibrates inresponse to the user encountering an object in a virtual world. Thehaptic device 180 can be a haptic mat that a user can be located on, asdescribed in detail with respect to FIG. 2. In other embodiments, thehaptic device 180 has a smaller form factor and is configured to providehaptic feedback to a hand of the user. In some embodiments, the hapticdevice 180 can be implemented for providing haptic feedback in anaugmented reality.

The VR console 110 provides media to the VR headset 105 for presentationto the user in accordance with information received from one or more of:the imaging device 135, the VR headset 105, and the VR input interface140. The VR console 110 may also instruct the haptic device 180 (e.g.,haptic mat) to provide haptic feedback. In the example shown in FIG. 1,the VR console 110 includes an application store 145, a tracking module150, and a virtual reality (VR) engine 155. Some embodiments of the VRconsole 110 have different modules than those described in conjunctionwith FIG. 1. Similarly, the functions further described below may bedistributed among components of the VR console 110 in a different mannerthan is described here.

The application store 145 stores one or more applications for executionby the VR console 110. An application is a group of instructions, thatwhen executed by a processor, generates content for presentation to theuser. Content generated by an application may be in response to inputsreceived from the user via movement of the VR headset 105 or the VRinterface 140. Examples of applications include: gaming applications,conferencing applications, video playback application, or other suitableapplications.

The tracking module 150 calibrates the VR system 100 using one or morecalibration parameters and may adjust one or more calibration parametersto reduce error in determination of the position of the VR headset 105.For example, the tracking module 150 adjusts the focus of the imagingdevice 135 to obtain a more accurate position for observed locators onthe VR headset 105. Moreover, calibration performed by the trackingmodule 150 also accounts for information received from the IMU 130.Additionally, if tracking of the VR headset 105 is lost (e.g., theimaging device 135 loses line of sight of at least a threshold number ofthe locators 120), the tracking module 150 re-calibrates some or all ofthe system environment 100.

The tracking module 150 tracks movements of the VR headset 105 usingslow calibration information from the imaging device 135. The trackingmodule 150 determines positions of a reference point of the VR headset105 using observed locators from the slow calibration information and amodel of the VR headset 105. The tracking module 150 also determinespositions of a reference point of the VR headset 105 using positioninformation from the fast calibration information. Additionally, in someembodiments, the tracking module 150 may use portions of the fastcalibration information, the slow calibration information, or somecombination thereof, to predict a future location of the headset 105.The tracking module 150 provides the estimated or predicted futureposition of the VR headset 105 to the VR engine 155.

The VR engine 155 executes applications within the system environment100 and receives position information, acceleration information,velocity information, predicted future positions, or some combinationthereof of the VR headset 105 from the tracking module 150. Based on thereceived information, the VR engine 155 determines content to provide tothe VR headset 105 for presentation to the user. For example, if thereceived information indicates that the user has looked to the left, theVR engine 155 generates content for the VR headset 105 that mirrors theuser's movement in a virtual environment. Additionally, the VR engine155 performs an action within an application executing on the VR console110 in response to an action request received from the VR inputinterface 140 and provides feedback to the user that the action wasperformed. In one example, the VR engine 155 instructs the VR headset105 to provide visual or audible feedback to the user. In anotherexample, the VR engine 155 instructs the haptic device 180 (e.g., hapticmat) to provide haptic feedback to the user.

Example Virtual Reality System

FIG. 2 is an example diagram of a user 205 on a haptic mat 200 of thevirtual reality system, in accordance with an embodiment. In someembodiments, the haptic mat 200 may be, e.g., the haptic device 180. Theuser 205 wears the VR headset 105 and views an image of the virtualworld provided from the VR console 110, as described in detail withrespect to FIG. 1. The haptic mat 200 provides haptic feedback to theuser 205 located on the haptic mat 200 in accordance with the imagepresented on the VR headset 105.

The haptic mat 200 is a surface that provides controlled haptic feedbackto a user 205 on the haptic mat 200 according to a control from the VRconsole 110. The haptic mat 200 includes a center plate 210 and aperiphery section 220 circumscribing the center plate 210, and actuators230. In one example, an edge (or a contour) of the haptic mat 200 is anedge 260 (or a contour) of the periphery section 220 away from thecenter plate. In different embodiments, the periphery section 220 may beomitted.

The center plate 210 transmits haptic feedback from the haptic mat 200to the user 205. The center plate 210 may have a circular, elliptical,or some other shape useful for transmitting haptic feedback. The user205 can be placed on the center plate 210 to receive the hapticfeedback. Haptic feedback can be provided from one side of the hapticmat 200 toward another side of the haptic mat 200 through the centerplate 210. Preferably, the center plate 210 is rigid such that a hapticfeedback wave 240 generated by one or more of the actuators 230 can bepropagated through the center plate 210. The center plate 210 iscomposed of, e.g., aluminum, steel, stainless steel, some other metal,some other material with a stiffness over N/m, or some combinationthereof.

In some embodiments, the haptic mat 200 generates haptic feedback viawave field synthesis. Huygens' principle proposes that a singularwavefront can be thought of as a distribution of point sources, whoseradial emission of energy through superposition overlay to exactly thatwavefront. Using this idea, the haptic mat 200 is able to generate awave field within the haptic mat 200 with specific 2-D spatial andtemporal mechanical vibrations by driving the actuators 230 with aspecific phase delay (e.g., depending on array geometry of the actuators230). Additional details of an example haptic mat are discussed in theAppendix.

The actuators 230 are coupled to the center plate 210 of the haptic mat200 and provide haptic feedback to the user 205. In one aspect, theactuators 230 are coupled to a bottom surface of the center plate 210,near a perimeter of the center plate 210. The actuators 230 may applyactuations by moving in 6 degrees of freedom. For example, the actuators230 may move forward/backward, up/down, left/right (translation in threeperpendicular axes) combined with rotation about three perpendicularaxes (i.e., pitch, yaw, and roll). The actuators 230 are electricallyactuated to induce motion in the center plate 210 in accordance withcommands from the VR console 110 to generate a haptic feedback wave 240.In some embodiments, some or all of the actuators 230 may also beconfigured to dampen a haptic feedback wave. For example, In FIG. 2, anactuator 230A may generate the haptic feedback wave 240, and one or moreother actuators 230 (e.g., actuator 230B) may be configured to activelydampen the haptic feedback wave 240.

In one embodiment, the actuator 230 suppresses a haptic feedback wave240 generated by another actuator 230, according to a prediction fromthe VR console 110. The actuator 230 can be operated according to aprediction from the VR console 110 that causes said another actuator 230to generate the haptic feedback wave 240. The VR console 110 determinesan estimated time of arrival of the haptic feedback wave at the actuator230 based on the information about the wave generated by said anotheractuator 230. For example, the VR console obtains a type of wave,frequency, amplitude, of the haptic wave generated, predicts theestimated time of arrival, and configures the actuator 230 to suppressthe haptic feedback wave through specific excitations to counteract thehaptic feedback wave at the predicted time. In some embodiments, afeedback based control mechanism, e.g., impedance regulated by an Opampactive filter, may be employed to drive actuators to actively suppressthe waves created by other actuators without the VR console 110.

FIG. 3A is a perspective view of an actuator 302, in accordance with anembodiment. In some embodiments, the actuator 302 may be, e.g., theactuator 230 of FIG. 2. In some embodiments, the actuator 302 includestwo magnets 310A and 310B. In addition, the actuator 302 includes afirst body 305A configured to create magnetic field to interact withmagnetic field of the first magnet 310A and a second body 305Bconfigured to create magnetic field to interact with magnetic field ofthe second magnet 310B. The first body 305A includes a first elongatedmember 330A composed of magnetic material (e.g., ferrite material) andcoils 335A and 335B coupled to the first elongated member 330A.Similarly, the second body 305B includes a second elongated member 330Bcomposed of magnetic material (e.g., ferrite material) and coils 335Cand 335D coupled to the second elongated member 330B. The first body305A and the second body 305B are coupled to each other throughconnecting members 320A, 320B, and 320C. In other embodiments, theactuator 302 includes different, more or fewer components than shown inFIG. 3A.

In one embodiment, the first body 305A, the second body 305B, and theconnecting members 320A, 320B, and 320C form a cubic structure as shownin FIG. 3A. For example, the third connecting member 320C faces thefirst connecting member 320A in the horizontal direction 380, and thesecond connecting member 320B faces the magnets 310A and 310B in thevertical direction 385, where each of the connecting members 320A, 320B,and 320C is elongated in a direction 395 orthogonal to the horizontaldirection 380 and the vertical direction 385 to couple the first body305A facing the first magnet 310A and the second body 305B facing thesecond magnet 310B.

Each magnet 310 (i.e., 310A and 310B) is coupled to the haptic mat 200,and configured to inject vibrations (or mechanical excitations) to thehaptic mat 200 according to the magnetic field applied to each magnet310. Specifically, the magnet 310 is pushed or pulled according to themagnetic pole of the magnet 310 and the magnetic field applied from acorresponding body 305. Preferably, the first magnet 310A and the secondmagnet 310B have similar shapes but opposite facing magnetic polarities.Alternatively, the first magnet 310A and the second magnet 310B may havethe same magnetic pole. In some embodiments, the magnets 310 areimplemented as permanent magnets with fixed magnetic poles. In otherembodiments, one or more of the magnets 310 are implemented aselectromagnets that are programmable.

FIG. 3B is a front view of the actuator 302 of FIG. 3A, in accordancewith an embodiment. The first magnet 310A includes a top portionincluding a top surface 312, and a bottom portion including a firstbottom surface 314A and a second bottom surface 314B. As shown in FIG.3B, the top surface 312 of the first magnet 310A is coupled to a surface(e.g., a bottom surface or a top surface) of the center plate 210. Inone implementation, the top portion of the first magnet 310A has acylindrical shape, where the top surface 312 of the first magnet 310A iscoupled to a bottom surface of the haptic mat 200. The bottom portion ofthe first magnet 310A includes the first bottom surface 314A facing afirst end of the first body 305A in a slanted direction of the verticaldirection 385. The bottom portion of first magnet 310A also includes asecond bottom surface 314B facing a second end of the first body 305A inanother slanted direction of the vertical direction 385. Each of thebottom surfaces 314A, 314B faces a respective end of the first body 305Ain a direction transverse to the orthogonal direction (i.e., verticaldirection 385) of the top surface 312 as shown in FIG. 3B.

The second magnet 310B has a similar structure of the first magnet 310A,hence the detailed description thereof is omitted herein for the sake ofbrevity. The first magnet 310A and the second magnet 310B with thestructure described above can move in a horizontal direction 380parallel to the top surface 312 of the magnet, a vertical direction 385perpendicular to the horizontal direction 380 of FIG. 3B, or anycombination thereof.

In one aspect, the first body 305A creates magnetic fields with a netmagnetic force that may not be aligned with facing directions of twoends of the first elongated member 330A. The first body 305A includes afirst elongated member 330A composed of the magnetic material (e.g.,ferrite material) and coils 335A and 335B coupled to each end of thefirst body 305A. According to the current supplied to a coil 335, acorresponding magnetic field can be created at a bottom surface of thefirst magnet 310A facing the end coupled to the coil 335.

In one embodiment, the first elongated member 330A includes fourportions 332A, 332B, 332C, and 332D to create magnetic fields with a netmagnetic force that may not be aligned with facing directions of twoends of the first elongated member 330A. In one implementation, thefirst elongated member 330A is structured where: one end of the firstportion 332A is coupled to the first end of first elongated member 330A;another end of the first portion 332A is coupled to one end of thesecond portion 332B through a first joint 338A; another end of thesecond portion 332B is coupled to one end of the third portion 332Cthrough a second joint 338B; another end of the third portion 332C iscoupled to one end of a fourth portion 332D through a third joint 338C;and another end of the fourth portion 332D is coupled to the second endof the first elongated member 330A, in a manner that both ends of thefirst elongated member 330A face the first magnet 310A. The firstportion 332A and the third portion 332C may be disposed in parallel toeach other, and the second portion 332B and the fourth portion 332D maybe disposed in parallel to each other. Preferably, each portion 332 iscoupled to another portion 332 in a perpendicular direction at acorresponding joint. Alternatively, each portion 332 is coupled toanother portion 332 in a non-perpendicular direction, while both ends ofthe first elongated member 330A face the first magnet 310A. In anotheraspect, the first elongated member 330A has a horse hoof shape.

The second elongated member 330B has a similar configuration as thefirst elongated member 330A to create magnetic fields with a netmagnetic force that may not be aligned with facing directions of twoends of the second elongated member 330B. Therefore, the detaileddescription thereof is omitted herein for the sake of brevity.

FIG. 3C is a bottom plan view of the actuator of FIG. 3A, in accordancewith an embodiment. In one embodiment, the first elongated member 330Aand the second elongated member 330B are coupled to each other throughconnecting members 320A, 320B, and 320C. The connecting members 320A,320B, and 320C are elongated in a direction 395 orthogonal to thevertical direction 385 and the horizontal direction 380. Each connectingmember 320 is coupled to a joint 338 of the first elongated member 330Aand a corresponding joint 348 of the second elongated member 330B.Specifically, one side of the first connecting member 320A is coupled tothe first joint 338A of the first elongated member 330A and another sideof the first connecting member 320A is coupled to a first joint 348A ofthe second elongated member 330B. Similarly, one side of the secondconnecting member 320B is coupled to the second joint 338B of the firstelongated member 330A and another side of the second connecting member320B is coupled to a second joint 348B of the second elongated member330B. Moreover, one side of the third connecting member 320C is coupledto the third joint 338C of the first elongated member 330A and anotherside of the third connecting member 320C is coupled to a third joint348C of the second elongated member 330B. Accordingly, the first body305A, the second body 305B, and the connecting members 320A, 320B, 320Cform a cubic crystal structure as shown in FIG. 3A.

FIG. 3D is a side view of the actuator 302 of FIG. 3A, in accordancewith an embodiment. In FIG. 3D, a side of the actuator 302 of FIG. 3Awith the connecting member 320C coupled to the first elongated member330A and the second elongated member 330B is shown. The magnets 310A and310B are coupled to the center plate 210. The first magnet 310A movesaccording to magnetic field induced by current flowing through the coil335B and the coil 335A (not shown in FIG. 3D). Similarly, the secondmagnet 310B moves according to magnetic field induced by current flowingthrough the coil 335D and the coil 335C (not shown in FIG. 3D). Thefirst magnet 310A and the second magnet 310B move in phase or out ofphase according to current supplied through coils 335 to generate adesired wave as described below.

Example Excitations

The actuator 302 disclosed herein can apply various excitations to thehaptic mat 200 by moving the magnets 310A and 310B, according to currentapplied to the coils 335. The actuator 302 can inject, for example, avertical sync excitation, horizontal sync excitation, vertical tiltexcitation, horizontal tilt excitation, or a combination of thereof tothe haptic mat 200. The vertical sync excitation herein refers to atranslational motion of the magnets 310A and 310B in the verticaldirection 385 or an opposite direction of the vertical direction 385together. The horizontal sync excitation herein refers to atranslational motion of the magnets 310A and 310B in the horizontaldirection 380 or an opposite direction of the horizontal direction 380together. The vertical tilt excitation herein refers to a translationalmotion of one of the magnets 310A and 310B in the vertical direction 385and the other of the magnets 310A and 310B in the opposite direction ofthe vertical direction 385. The horizontal tilt excitation herein refersto a translational motion of one of the magnets 310A and 310B in thehorizontal direction 380 and the other of the magnets 310A and 310B inthe opposite direction of the horizontal direction 380.

In one aspect, the actuator 302 applies the vertical sync excitation bymoving the magnets 310A and 310B in the vertical direction 385.Specifically, the magnets 310A and 310B can move up in the verticaldirection 385 or down in the opposite direction of the verticaldirection 385 together by supplying current to the coils 335A, 335B,335C, and 335D in phase.

Similarly, the actuator 302 applies the horizontal sync excitation bymoving the magnets 310A and 310B in the horizontal direction 380.Specifically, the magnets 310A and 310B can move in the horizontaldirection 380 or in the opposite direction of the horizontal direction380 together by supplying current to the coils 335A, and 335C in phase,and to the coils 335B, and 335D out of phase.

In another aspect, the actuator 302 applies the vertical tilt excitationby moving one of the magnets 310A and 310B in the vertical direction385, and the other of the magnets 310A and 310B in the oppositedirection of the vertical direction 385. Hence, the magnets 310A and310B can be actuated like a seesaw in the vertical direction 385 bysupplying current to the coils 335A and 335B in phase, and to the coils335C and 335D out of phase.

Yet in another aspect, the actuator 302 applies the horizontal tiltexcitation by moving one of the magnets 310A and 310B in the horizontaldirection 380, and the other of the magnets 310A and 310B in theopposite direction of the horizontal direction 380. Hence, the magnets310A and 310B can be actuated like a seesaw in the horizontal direction380 by supplying current to the coils 335A and 335D in phase, and to thecoils 335B and 335C out of phase.

Although four types of excitations are described above, the actuator 302can simultaneously perform two or more excitations described above tocontrol the movement of the magnets 310 by controlling magnitude,frequency, and a phase of current supplied to each coil 335.

Advantageously, the actuator 302 having the cubic crystal structure asdisclosed herein can apply transversal excitation, thereby allowing thewave to propagate in a specific direction. For example, through variouscombinations of the excitations listed above, the actuator 302 cangenerate a forward traveling wave by applying a whipping actuation onthe haptic mat 200. As a result, the wave can be propagated in acontrolled direction without energy being scattered.

Moreover, the actuator 302 can be configured to suppress the wavegenerated from another actuator according to a prediction from the VRconsole 110. Accordingly, damping elements to reduce reflection of thehaptic feedback wave may be eschewed.

Additional Configuration Information

The foregoing description of the embodiments has been presented for thepurpose of illustration; it is not intended to be exhaustive or to limitthe patent rights to the precise forms disclosed. Persons skilled in therelevant art can appreciate that many modifications and variations arepossible in light of the above disclosure.

The language used in the specification has been principally selected forreadability and instructional purposes, and it may not have beenselected to delineate or circumscribe the inventive subject matter. Itis therefore intended that the scope of the patent rights be limited notby this detailed description, but rather by any claims that issue on anapplication based hereon. Accordingly, the disclosure of the embodimentsis intended to be illustrative, but not limiting, of the scope of thepatent rights, which is set forth in the following claims.

What is claimed is:
 1. An actuator comprising: a first magnet having apole, the first magnet coupled to a plate of a haptic mat; and a firstbody, the first body comprising: a first elongated member that iscomposed of a magnetic material, a first end of the first elongatedmember facing a first surface of the first magnet, a second end of thefirst elongated member facing a second surface of the first magnet, afirst coil coupled to the first end of the first elongated member, and asecond coil coupled to the second end of the first elongated member,wherein the first coil and the second coil are configured to be drivenwith a first electric current and a second electric current,respectively, that together induce a magnetic field within the firstelongated member to cause a motion of the first magnet relative to thefirst body, the motion of the first magnet generating a portion of ahaptic feedback wave within the plate.
 2. The actuator of claim 1,further comprising: a second magnet having another pole, the secondmagnet coupled to the plate of the haptic mat; and a second body, thesecond body comprising: a second elongated member that is composed ofthe magnetic material, a first end of the second elongated member facinga first surface of the second magnet, a second end of the secondelongated member facing a second surface of the second magnet, a thirdcoil coupled to the first end of the second elongated member, and afourth coil coupled to the second end of the second elongated member,wherein the third coil and the fourth coil are configured to be drivenwith a third electric current and a fourth electric current,respectively, that together induce another magnetic field within thesecond elongated member to cause a motion of the second magnet relativeto the second body, the motion of the second magnet together with themotion of the first magnet generating another portion of the hapticfeedback wave within the plate.
 3. The actuator of claim 2, wherein athird end of the first body disposed away from the first magnet iscoupled to a third end of the second body disposed away from the secondmagnet.
 4. The actuator of claim 3, wherein the first body and thesecond body are coupled to each other to form a ferrite.
 5. The actuatorof claim 2, wherein the first body comprises a first joint, a secondjoint, and a third joint, and wherein the second body comprises a fourthjoint, a fifth joint, and a sixth joint, the actuator furthercomprising: a first connecting member coupled to the first joint of thefirst body and the fourth joint of the second body; a second connectingmember coupled to the second joint of the first body and the fifth jointof the second body; and a third connecting member coupled to the thirdjoint of the first body and the sixth joint of the second body.
 6. Theactuator of claim 5, wherein a portion of the first elongated memberbetween the first end of the first elongated member and the first jointis parallel to a portion of the first elongated member between thesecond joint and the third joint, and wherein a portion of the firstelongated member between the second end of the first elongated memberand the third joint is parallel to a portion of the first elongatedmember between the first joint and the second joint.
 7. The actuator ofclaim 5, wherein a portion of the second elongated member between thefirst end of the second elongated member and the fourth joint isparallel to a portion of the second elongated member between the fifthjoint and the sixth joint, and wherein a portion of the second elongatedmember between the second end of the second elongated member and thesixth joint is parallel to a portion of the second elongated memberbetween the fourth joint and the fifth joint.
 8. The actuator of claim5, wherein the first connecting member, the second connecting member,and the third connecting member are parallel to each other.
 9. A methodcomprising: applying a first electric current to a first coil and asecond electric current to a second coil, the first coil coupled to afirst end of a first elongated member, the second coil coupled to asecond end of the first elongated member, the first end of the firstelongated member facing a first surface of a first magnet, the secondend of the first elongated member facing a second surface of the firstmagnet, the first electric current applied to the first coil and thesecond electric current applied to the second coil configured to movethe first magnet away from the first end and the second end of the firstelongated member.
 10. The method of claim 9, further comprising:applying a third electric current to a third coil and a fourth electriccurrent to a fourth coil, the third coil coupled to a first end of asecond elongated member, the fourth coil coupled to a second end of thesecond elongated member, the first end of the second elongated memberfacing a first surface of a second magnet, the second end of the secondelongated member facing a second surface of the second magnet, the thirdelectric current applied to the third coil and the fourth electriccurrent applied to the fourth coil configured to move the second magnettowards the first end and the second end of the second elongated member,wherein the first elongated member and the second elongated member arecoupled to each other through a connecting member.
 11. The method ofclaim 9, further comprising: applying a third electric current to athird coil and a fourth electric current to a fourth coil, the thirdcoil coupled to a first end of a second elongated member, the fourthcoil coupled to a second end of the second elongated member, the firstend of the second elongated member facing a first surface of a secondmagnet, the second end of the second elongated member facing a secondsurface of the second magnet, the third electric current applied to thethird coil and the fourth electric current applied to the fourth coilconfigured to move the second magnet away from the first end and thesecond end of the second elongated member, wherein the first elongatedmember and the second elongated member are coupled to each other througha connecting member.
 12. An actuator comprising: a first magnet having apole, the first magnet coupled to a plate; and a first body, the firstbody comprising: a first elongated member, a first end of the firstelongated member facing a first surface of the first magnet, a secondend of the first elongated member facing a second surface of the firstmagnet, a first coil coupled to the first end of the first elongatedmember, and a second coil coupled to the second end of the firstelongated member, wherein the first coil and the second coil areconfigured to be driven with a first electric current and a secondelectric current, respectively, that together induce a magnetic fieldwithin the first elongated member to cause a motion of the first magnetrelative to the first body, the motion of the first magnet generating aportion of a mechanical wave within the plate.
 13. The actuator of claim12, further comprising: a second magnet having another pole, the secondmagnet coupled to the plate; and a second body, the second bodycomprising: a second elongated member, a first end of the secondelongated member facing a first surface of the second magnet, a secondend of the second elongated member facing a second surface of the secondmagnet, a third coil coupled to the first end of the second elongatedmember, and a fourth coil coupled to the second end of the secondelongated member, wherein the third coil and the fourth coil areconfigured to be driven with a third electric current and a fourthelectric current, respectively, that together induce another magneticfield within the second elongated member to cause a motion of the secondmagnet relative to the second body, the motion of the second magnettogether with the motion of the first magnet generating another portionof the mechanical wave within the plate.
 14. The actuator of claim 13,wherein a third end of the first body disposed away from the firstmagnet is coupled to a third end of the second body disposed away fromthe second magnet.
 15. The actuator of claim 14, wherein the first bodyand the second body are coupled to each other to form a ferrite.
 16. Theactuator of claim 13, wherein the first body comprises a first joint, asecond joint, and a third joint, and wherein the second body comprises afourth joint, a fifth joint, and a sixth joint, the actuator furthercomprising: a first connecting member coupled to the first joint of thefirst body and the fourth joint of the second body; a second connectingmember coupled to the second joint of the first body and the fifth jointof the second body; and a third connecting member coupled to the thirdjoint of the first body and the sixth joint of the second body.
 17. Theactuator of claim 16, wherein a portion of the first elongated memberbetween the first end of the first elongated member and the first jointis parallel to a portion of the first elongated member between thesecond joint and the third joint, and wherein a portion of the firstelongated member between the second end of the first elongated memberand the third joint is parallel to a portion of the first elongatedmember between the first joint and the second joint.
 18. The actuator ofclaim 16, wherein a portion of the second elongated member between thefirst end of the second elongated member and the fourth joint isparallel to a portion of the second elongated member between the fifthjoint and the sixth joint, and wherein a portion of the second elongatedmember between the second end of the second elongated member and thesixth joint is parallel to a portion of the second elongated memberbetween the fourth joint and the fifth joint.
 19. The actuator of claim16, wherein the first connecting member, the second connecting member,and the third connecting member are parallel to each other.